Allen keys, famous for their inclusion in flatbed kitset furniture, are efficiently designed screwdrivers that provide excellent torque. Allen keys are known by other names specifically hex-key wrenches, hex keys or Allen wrenches. They are characterized by their curved L shape and a hexagonal cross section, used to insert into matching fasteners.
The hexagonal fasteners that Allen keys are designed for are easier to tighten and have better safety. They do not protrude and there is less chance of stripping the screw or the screwdriver slipping. Allen keys are commonly used for fasteners on machinery and engines to avoid the danger of extended fasteners, especially around pulleys or belts.
Allen keys can be purchased in both imperial and metric sizing. Most sets range from around 1.27mm up to 10mm or 1/16 to 5/16. For very fine precision work sets with tiny .7mm Allen keys are available.
Types of Allen Keys
The L-shape can be used from either end, depending on how much leverage is required and the tightness of the space. The L-end can be shortened for work in tight spaces.
Straight Allen keys come with a handle that allows more control over the tightening action and are similar to other types of single screwdrivers
For extra torque for hard to loosen hexagonal fasteners, the T-handle comes into action.
For the busy tradesman, a folding Allen key makes a lot of sense. Designed similarly to a pocket knife, Allen keys of multiple sizes can be carried in the one device. Once unfolded, the ‘pocket’ provides a handle for better leverage.
Allen Key Variations
A variety of the Allen Key is the ball end, which is applied to one end of the wrench. The ball end helps prevent over tightening and is also easier to insert into the fastener. Ball end Allen keys can fit into a min-ratchet driver or adjustable screwdriver for more leverage. Magnetic ball ends can be inserted into the bolt and hold it captive while manipulating into position. Though the ball-end has many advantages, the straight end Allen keys are recommended for jobs where high-strength is required.
The Hex-plus design has slightly angled edges around the hexagonal end. This design allows bolts that have been rounded and are difficult to remove with a normal Allen key to be taken out of their spot. The concave edge provides a better grip for difficult fasteners.
Who is Allen?
The original hex screw and screwdriver was designed and patented by the W.G. Allen from the Allen Manufacturing Company in 1909 as a fastener that did not protrude from heavy machinery. Even though other hex fasteners had been patented both before and after, the Allen name has stuck.
Allen keys or wrenches, hex-wrenches or keys, however they are termed remain a safe and secure way to join machinery parts without protruding parts causing a safety hazard. Visit RSOnline for more information and a wide range of Allen Key sets.